**Subject :**Microwave Engineering

## Microwave cavities

**Introduction : -
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In general, a cavity resonator is a metallic enclosure that confines the electromagnetic energy. The stored electric and magnetic energies inside the cavity determine its equivalent inductance and capacitance. The energy dissipated by the finite conductivity of the cavity walls determines its equivalent resistance. In practice, the rectangular-cavity resonator, circular-cavity resonator, and reentrant-cavity resonator are commonly used in many microwave applications. Theoretically a given resonator has an infinite number of resonant modes, and each mode corresponds to a definite resonant frequency. When the frequency of an impressed signal is equal to a resonant frequency, a maximum amplitude of the standing wave occurs, and the peak energies stored in the electric and magnetic fields are equal. The mode having the lowest resonant frequency is known as the dominant mode.

**Types of microwave cavities : -
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The most common and popular microwave cavities are :

**1. Rectangular Cavity Resonator
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**2. Circular Cavity Resonator
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**3. Semicircular Cavity Resonator**